Although AS affect cortisol synthesis in vitro, their impact in vivo is not that significant.
The anti-glucocorticoid activity is caused by glucocorticoid receptor antagonism.
All AS in general antagonize the glucocorticoid receptor...
Testosterone, dihydrotestosterone, trenbolone acetate, and zeranol alter the synthesis of cortisol in bovine adrenocortical cells.
Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
...The objective of this study was to examine the effect of anabolic steroids (testosterone, T; dihydrotestosterone, D; trenbolone acetate, B; and zeranol, Z) on cortisol synthesis by cultured bovine adrenocortical cells...
.."The suppression of cortisol synthesis did not differ between B and T or between B and D...
Use of trenbolone acetate and estradiol in intact and castrate male cattle: effects on growth, serum hormones, and carcass characteristics.
Hunt DW, Henricks DM, Skelley GC, Grimes LW.
Clemson University, SC 29634.
The effects of anabolic implant on growth, carcass characteristics, and serum hormones were examined in 30 young bulls and steers fed a growing diet then a finishing diet. In a 2 X 3 factorial arrangement, steers and bulls received an implant of trenbolone acetate (TBA), TBA and estradiol-17 beta (E2), or no implant. Blood samples were taken serially (every 20 min for 6 h) at intervals during the growing and finishing phases. Percentage of DM, fat, protein, and ash and Warner-Bratzler shear test were measured and taste panel evaluations of the 9-10-11 rib section were obtained. Treatment with TBA and E2 increased weight gain in steers but not in bulls. There were no differences in feed efficiency, serum growth hormone (GH), and cortisol concentrations between bulls and steers or between treated groups and controls in bulls or steers
The effect of manipulating growth in sheep by diet or anabolic agents on plasma cortisol and muscle glucocorticoid receptors.
.." 3. Trenbolone acetate treatment reduced the binding capacity of sheep skeletal muscle for cortisol within 2 d of implantation..."
J Steroid Biochem 1988 Jun;29(6):575-81 Related Articles, Links
Evidence for sex-dependent anabolic response to androgenic steroids mediated by muscle glucocorticoid receptors in the rat.
..The results suggest that anabolic steroids can act via muscle glucocorticoid receptors, thereby antagonizing the catabolic activity of endogenous glucocorticoids...
Am J Physiol 1975 Nov;229(5):1381-6 Related Articles, Links
Interaction of anabolic steroids with glucocorticoid receptor sites in rat muscle cytosol.
Mayer M, Rosen F.
While glucocorticoid hormones act catabolically on skeletal muscle through their binding to glucocorticoid-specific receptors in the cytosol, androgens exert anabolic responses but no androgen-specific binding proteins could be detected in this responsive tissue. However, various nonradioactive androgens were effective in displacing labeled dexamethasone or cortisol from their respective cytoplasmic receptors in muscle, both in vitro and in vivo. The inhibition of glucocorticoid binding by androgens is competitive, and could be observed following a single or repeated administration of the androgens to adrenalectomized-castrated animals. The synthetic androgen fluoxymesterone and the hormone testosterone displayed Ki values of 7.5 X 10(-6) M and 1 X 10(-5) M, respectively, for the inhibition of [3H]dexamethasone binding in muscle cytosol. On the basis of competition experiments it is postulated that interaction of androgens with glucocorticoid receptors prevents the binding of glucocorticoids and might be responsible in part for the anabolic effects of pharmacologic doses of androgens in muscle.
If testosterone treatment causes PRL increase, for example, that increase doesn't have much to do with its glucocorticoid receptor antagonism, it's caused by elevated estrogen and can be prevented by use of SERMs or aromatase inhibitors...